Slack adjuster



ATTORNEY Oct. 16, 1951 M. D. OHERN SLACK ADJUSTER Filed NOV. 22, 1945 Patented Oct. 16, 1951 SLACK ADJ USTER Maurice D. OHern, Hammond, Ind., assignor to American Steel Foundries, Chicago, Ill., a corporation of New Jersey Application November 22, 1946, Serial No. 711,620

(Cl. I4-522) 4 Claims.

My invention relates to railway brake rigging and more particularly to a slack adjuster device designed to be associated with an end of a pull rod affording a connection between the associated truck levers utilized in said rigging.

Y An object of my invention is to provide a simple and durable slack adjuster comprising a twopiece fulcrum block, the pieces being symmetrical in design and adaptable to be relatively cheaply manufactured by the forging method, thus eliminating much of the machining or grinding incident to finishing a cast block.

Another object of the invention is to provide aslack adjuster arrangement in -which the parts may be easily and quickly assembled and dismantled without distorting any of the parts.

A further object of my invention is to vprovide a reliable slack adjuster arrangement which will meet all necessary requirements under operating conditions.

These and other objects will be apparent from the specification and drawings, wherein:

Figure l is a plan view of the slack adjuster constructed in accordance with the present invention with parts being shown in section;

Figure 2 is a side elevational view of the same; Y Figure 3 is a top plan View illustrating half of the fulcrum block as forged, Figures 4 and 5 respectively areright and left end elevations of the structure shown in Figure 3; and

, Figure 6 is a transverse sectional view taken substantially in the plane indicated by the line 6-6 of Figure 1.

In the embodiment of the device selected for illustration in the drawings, the brake rod 2 is disclosed having an open rectangular frame 4 providing spaced arms 6, 6 which are joined at the end opposite the rod by the hub 8. Between the arms 6, 6 are positioned a pair of elongated symmetrical members Ill, I (Figure 3) the members of the pair being reversely or oppositely arranged side by side and together forming a U-shaped yoke or fulcrum block, each of said members comprising a web I2 engaging a side of the adjacent arm 6 and each web I2 has an inturned4 end portion I4. The end portions I4, I4 of the pair abut each other as at I6 and form the head of the yoke and with said webs I2, I2 define the slot I8 within which is received a lever I5, fragmentarily shown in phantom lines in Figure 2, the lever having pivotal connection with the yoke through the pin 20 extending therethrough, said pin, at opposite ends thereof, projecting into aligned complementary openings 2 2, 22 in the said webs I2, I2.

lilil Each web I2 is provided on the outer face thereof with undercut grooves 24 and 26 (Figures 4 and 5), said grooves being disposed respectively adjacent the upper and lower portions of the abutting arm 6 of the frame, it being noted that the grooves on one of said members are oppositely arranged to the grooves on the other of said members.

To interlock the members with the frame, a pair of identical U-shaped top and bottom plates 28, 28 are provided, each having longitudinally extending legs 30, 30. The legs of the top plate are received within the said slots 24, 24 and the legs of the bottom plate t into the slots 26, 26, the legs of said plates respectively slidably engaging the upper and the lower portions of the arms 6, 6.

It will be understood that the lever I5 inter-Y posed between the members I0, IIJ serves to hold them apart and against the adjacent faces of the arms 6,6, said faces abutting the ends of the pin 20 and preventing said pin from slipping out endwise relative to said members, and the plates 28, 28 keep the assembly thus far described from falling out of the frame.

The abutting end portions of the members I 0, I0 may be recessed as at 32, 32 (Figure 5) to form a socket into which is projected an end 34 of the adjusting screw 36. The abutting end 1 portions I4, I4 may also be recessed as at 31. 31 as by broaching to form an opening for reception of the pin 38 securing said members I0, I0 to said screw 36 and plates 28, 28.

It may be noted in the drawings that in Figures 3-5 the recess 31 is not shown. These views are intended to depict the half block as forged. The recess 31 is formed after the forging process is completed.

The other end of the screw may be threaded into a nut 40 rotatably mounted within the hub 8, said nut being provided with an enlarged end 42 engaging the inner surface of said hub and also being provided with an extension extending through said hub, said lextension having a plurality of flat surfaces 44 whereby the same may be easily gripped by any suitable tool for imparting rotation to the nut.

For preventingendwise movement of the nut 4U a collar 46 is suitably secured as by press tting on the extension, the collar engaging the outside surface of the hub 8 and thus, with the enlarged end 42, serves to hold the nut in position in lthe hub 8 against any tension exerted by the fulcrum block.

It will be appreciated that by rotating the nut the screw is moved inwardly or outwardly of the extension, said screw imparting movement to the fulcrum block longitudinally of the frame for adjusting the position of the same within said frame, and it will thus be seen that movement of the block upon the arms 6, 6 will function to vary the relative position of the truck lever with relation to the brake rod.

To assemble my novel slack adjuster, the nut 4U is fitted in the opening in hub 8 with its flange 42 in abutment with the inner side of the hub and the nut extension projecting outwardly of the hub. The sleeve 46 is then secured, as by press fitting, to the nut extension in a position against the outer side of hub 8. Then screw 36 is threaded into the nut as seen in Figure l. Thereafter the fulcrum block and lever are assembled by placing parts l0, In oi portions, said lever serving to maintain said side the block against opposite sides of the lever and inserting pin 20 through openings 22 in members Ii! and a complementary opening in the lever. The lever, block and pin subassembly is then entered from the top or bottom of the frame into the space between arms B, 6 at the end of frame adjacent rod 2. This subassernbly is thus spaced from the hub 8 longitudinallg7 of the frame. Then plates 28, 28 are placed against the upper and lower edges of arms 8, 6, respectively, adjacent hub 8 and moved in a direction toward the rod 2 entering the inner edges of legs 30, 30 of the top plate in grooves 24, 2d in the remote sides of members IQ, l and the inner edges of legs 30, 30 of the bottom plate 28 in the grooves 26, 26 in the remote sides of members I0, I0. This subassembly, with the legs 30, 30 of the plates overlapping the top and bottom edges of arms 6, 6, is slidably moved in the frame toward hub 8 until end 3L. or" screw 36 enters the socket 32 in portions Ii, I4 of members l, l0. The bolt 38 is then inserted through the end 34 of the screw and recesses 3i in portions I4, I4 of the members It, l0 and through openings in the top and bottom plates, and a nut and cotter key are applied to the threaded end of the bolt.

It is to be understood that I do not wish to be limited by the exact embodiment of the device shown which is merely by way of illustration and not limitation as various and other forms of the device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

I claim:

1. In a brake slack adjuster. a frame including spaced arms, brake lever fulcrum means comprising a pair of members bilaterally symmetrical with respect to each other and arranged to form a fulcrum block between said arms, each member including a side portion disposed along the adjacent arm and a transverse portion, the transverse portions of respective members being aligned laterally of said frame and being formed with complementary recesses at adjacent ends defining a socket, the axis of which extends longitudinally of said block, adjusting means for said fulcrum means operatively associated with the' frame and including a screw extending into said socket, spaced retainer elements disposed at opposite edges of said arms and each comprising spaced legs overlapping the respective arms and extending into oppositely arranged grooves in the side portions of saidmembers for interlocking said members with said arms, each retainer including a crossp'iece interconnecting portions in spaced relationship and said pin maintaining said members in assembled vrelationship with the transverse portions thereof in alignment laterally of said arms, said members being spaced from said arms when said transverse portions abut each other and being movable transversely of said arms without disconnecting from said bolt or pin to accommodate levers of several thicknesses between said side portions.

2. In a slack adjuster, a frame including spaced arms, brake lever fulcrum means therebetween and including a pair of members bilaterally symmetrical with respect to each other forming a fulcrum block, said members comprising abutting end portions forming the head of the block and extending transversely of said arms, each member comprising a side portion extending along the adjacent arm, plates disposed above and below said frame and interlocked with said side portions, said plates extending across said end portions. said end portions being formed and arranged along their adjacent ends to provide a socket, the axis of which extends longitudinally of the frame, adjusting means for said block operatively connected to the frame and including a screw extending into the socket, said end portions being formed with recesses at their adjacent ends to define coaxial openings communicating with said socket and extending transversely thereof, a bolt extending through said openings, said screw and aligned openings in said plates, said members being movable away from each other a limited distance between said arms to vary the width of the slot defined between said side portions.

3. In a brake slack adjuster, a frame including spaced arms, a pair of members bilaterally symmetrical with respect to each other and loosely fitted between said arms and slidably interlocked therewith and forming a fulcrum block, said members having side portions adjacent respective arms and transverse portions extending toward each other, said side portions defining a lever-receiving slot therebetween, adjusting means for said block operatively connected to said frame and having a screw extending between said arms, and a connection between said transverse portions and said screw and including a bolt projecting lengthwise through said screw and extending at opposite sides into recesses within adjacent ends of said transverse portions, said connection accommodating movement of said members transversely of said frame between said arms to vary the width of the slot between said side portions.

4. A fulcrum block member comprising a side portion and an end portion extending transversely of said side portion. said side yportion being formed with spaced grooves on its external side extending longitudinally thereof and said end portion being formed in the end thereof remote from said side portion with a socket recess,

the axis of which extends longitudinaliyof said member and with pin hole recesses communieating with said socket recess and extending transversely thereof.

MAURICE D. OHERN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date Baselt Nov. 5, '1935 Whitney Aug. 5 1924 Whitney Aug. 26, 1924 Hedgecock Sept. 21, 1926 Blakeslee Feb. 9, 1932 Mitchell Feb. 9, 1932 Bushman May 9, 1933 

